Yeast Nutrients assist the wine yeasts in producing a complete and rapid fermentation. It is recommended for use in all fermentations. Yeast Nutrient also provides a singular source of nitrogen for the yeast to utilize during the fermentation process. Nitrogen is typically found to be naturally lacking in most wine musts. Insufficient levels of nitrogen usually result in a sluggish fermentation and can also lead to the production of unwanted fusel oils, which can be detected as off-flavors in a finished wine.